When cells experiencing DNA damage fail to repair themselves, they send a signal to their neighbors letting them know they're in trouble. The discovery, which shows that a process dubbed the DDR (DNA Damage Response) also ...

Excessive exposure to ultraviolet (UV) radiation of sunlight can result in skin damage and may even induce skin cancers. Irradiation with UV light causes mutations in the DNA, which can interfere with or even inhibit the ...

Switching off a key DNA repair system in the developing nervous system is linked to smaller brain size as well as problems in brain structures vital to movement, memory and emotion, according to new research led by St. Jude ...

When cells undergo potentially catastrophic damage, for example as a result of exposure to ionizing radiation, they must make a decision: either to fix the damage or program themselves for death, a process called apoptosis.

Mycobacterium tuberculosis is arguably the world's most successful infectious agent because it knows how to avoid elimination by slowing its own growth to a crawl. Now, a report in the July 10 issue of the journal Cell, a ...

Like doctors making house calls, some DNA repair enzymes can relocate to the part of the cell that needs their help, a collaborative team of scientists at Emory University School of Medicine has found.

Some DNA repair enzymes can become double-edged swords - If they work too slowly, they can block necessary cell maintenance and contribute to cell death. This could explain the somewhat mysterious success of the widely used ...

In this week's issue of Science Signaling (22 January, 2013), Danen and colleagues of the Division of Toxicology of LACDR report novel insights into the question how stem cells decide to commit suicide when their DNA is damaged.

DNA repair

DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as UV light and Radiation can cause DNA damage, resulting in as many as 1 million individual molecular lesions per cell per day. Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions induce potentially harmful mutations in the cell's genome, which affect the survival of its daughter cells after it undergoes mitosis. Consequently, the DNA repair process is constantly active as it responds to damage in the DNA structure.

The rate of DNA repair is dependent on many factors, including the cell type, the age of the cell, and the extracellular environment. A cell that has accumulated a large amount of DNA damage, or one that no longer effectively repairs damage incurred to its DNA, can enter one of three possible states:

The DNA repair ability of a cell is vital to the integrity of its genome and thus to its normal functioning and that of the organism. Many genes that were initially shown to influence lifespan have turned out to be involved in DNA damage repair and protection. Failure to correct molecular lesions in cells that form gametes can introduce mutations into the genomes of the offspring and thus influence the rate of evolution.